#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main()
{
    const char *filename = "./record.txt";
    int fd = open(filename, O_RDWR | O_CREAT, 0644);
    if (fd == -1)
    {
        perror("open error:");
        exit(-1);
    }
    printf("fd = %d\n", fd);

    const char *buffer = "hello world!!!";
    int writeBytes = write(fd, (void *)buffer, strlen(buffer));
    printf("writeBytes = %d\n", writeBytes);

    close(fd);
}